Why do these guys always make fun of me when I put up a new pic of myself on fb?

Ok so these guys go to a different school but one of them basically got shutdown by my bff recentlyish who he wanted to go out with...so they kind of dislike us now. but they have this inside joke about me taking modelish pics of myself? i really don't take a lot of pics of myself and post them like I know ALOT of people do( some have like 50) but i have been guilty of it occasionally but i don't usually put them up(i have like 4) but when I put one up when i've had the same pro pic for forever they always comment on it being like blue steel or hmmm this ones average not gonna get that marc jacobs campaign..i know it might all just be kidding and a little bitterness but its kind of annoying. and i already have low self esteem. i mean why do they stalk my page anyway?